#include<bits/stdc++.h>

using namespace std;

#define rep(i, l, n) for(int i = int(l); i < int(n); ++i)
#define ll long long
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()

template<class T> bool chmin(T &a, T b) {if(a > b) {a = b; return true;} return false;}
template<class T> bool chmax(T &a, T b) {if(a < b) {a = b; return true;} return false;}
template<class T> using spq = priority_queue<T, vector<T>, greater<T>>;

// bool -> Yes/No
string answer(bool b) {return b ? "Yes" : "No";}

void fix(int k) {cout << fixed << setprecision(k);}

const int inf = 1000000009;
const long long INF = 2000000000000000009;
const long double eps = 1e-12;
const long double pi = acos(-1);
int dx[] = {0, -1, 0, 1, -1, -1, 1, 1}, dy[] = {1, 0, -1, 0, 1, -1, -1, 1};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    string s; cin >> s;
    int a = s[0] - '0', b = s[1] - '0', c = s[2] - '0';
    cout << answer(a + c == b) << '\n';
}